Sun Microsystems has quietly begun selling Fujtsu's PrimePower line of Unix servers, a first step in a plan to unify the two companies' Sparc-based product lines by 2006.

The two companies, which have collaborated on developing the Sparc processor architecture since the 1980s, announced plans last year to co-develop a new line of Sparc systems, called the Advanced Product Line (APL), that will replace the Sun Fire and PrimePower machines sold by Sun and Fujitsu.

As part of the arrangement, they pledged to begin distributing each other's products, a step that has now been taken, according to David Yen, executive vice president of Sun's Scalable Systems Group.

For Sun, distribution of the PrimePower servers began last month, said Yen. He said that the arrangement gives Sun access to markets, particularly with the high-end PrimePower servers, that it might not otherwise reach.

Sun is selling seven models of PrimePower servers, ranging from the dual-processor PrimePower 250 to the 128-chip PrimePower 2500, according to the company's Web site. The products are available in "select geographic areas," the site says.

Fujitsu also offers a wide array of Sun Fire servers on its Japanese Web site.

The arrangement also gives Sun time to accustom its sales and service forces to Fujitsu's systems, said Gordon Haff, an analyst with Illuminata, in Nashua, New Hampshire. "Probably both companies saw it as a logical step in moving toward having a more integrated product line," he said.

The integrated APL, which has been code-named Olympus, will begin shipping in 2006, Yen said. It will be based on version VI of the Sparc64 processor that Fujitsu uses for PrimePower, but the systems themselves will be built by both companies.

The transition to Fujitsu's processors will allow Sun to focus on its next generation of "throughput computing" chip designs while taking advantage of Fujitsu's own processor development efforts at the same time.

But the Fujitsu relationship and Sun's increased focus on Advance Micro Devices' Opteron processor also raises questions about the role that the Sparc architecture, long considered among the company's crown jewels, will play in the Sun's future, said Rainer Kleinresing, head of the computer group at the Max Planck Institute for Mathematics in the Sciences, in Leipzig, Germany. "I don't know whether Sparc will play that kind of role in the future," he said. "You can do pretty much everything with the Opteron system that you can do with the Sparc system."

Sun's PrimePower offerings can be found at http://www.sun.com/servers/fujitsu/